The present invention relates in general to high-voltage (HT) power supply units, particularly for X-ray sources, which units are biodegradable.
Conventional HT power supply units include components which are encased in electrically insulating cases. These components are arranged in an earthed box which is vacuum filled with an electrically insulating and cooling medium. The casings of the components are generally made by injection-molding of plastic. These injection-molded plastic casings need to be free of geometric defects and not to contain inclusions of gas which will detract from electrical insulation.
The plastic insulating casings and the insulating oil represent most (greater than 60% by volume) of the HT power supply unit, and this poses problems with recycling and safety and with respect to the environment.
Furthermore, it would be desirable to choose the thickness of the casings to suit the strength of the surrounding electrical field. Altering the thickness in this way is not compatible with injection-molding techniques which require a constant thickness in order to avoid geometric defects and/or inclusions of gas.
It would be desirable to provide a HT power supply units in which the materials used to insulate the electrical components readily allow the thickness of the insulation to be altered to suit the strength of the electric field that there is around the component and which are preferably biodegradable.